Apparatus for Automating the Counting of Sharps Using RFID Tags

ABSTRACT

In accordance with the teachings described herein, systems and methods are provided for counting sharps returned to a container. An example method of counting sharps returned to a container having at least two layers of penetrable conductive material includes periodically checking a plurality of circuits formed by the first and second layers of material to determine if each circuit is open or closed, and keeping a count of the number of closed circuits.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is continuation of U.S. patent application Ser. No.14/629,088, filed Feb. 23, 2015, and entitled “Apparatus for Automatingthe Counting of Sharps Using RFID Tags,” which is a divisional of U.S.patent application Ser. No. 13/157,948, filed Jun. 10, 2011, andentitled “Method and Apparatus for Automating the Counting of SharpsUsing RFID Tags,” which claims priority to and benefit from U.S.Provisional Patent Application No. 61/353,490, filed on Jun. 10, 2010,and entitled “Method and Apparatus for Automating the Counting of SharpsUsing RFID Tags,” the entirety of each of which is incorporated hereinby reference in their entirety.

BACKGROUND

The present disclosure is directed to methods and apparatus for thecounting of needles, scalpel blades, and other sharps and, moreparticularly, to the application of radio frequency identificationdevices (RFID) used to automate such counts.

This disclosure addresses the issue of counting sharps in and around theoperating room. Current technology automates the counting of some itemsin the operating room, such as surgical sponges, by affixing an RFID tagto the item. Objects such as needles and scalpel blades are notconducive to tagging because of their small size and because the smoothprofile of the object is essential to the function of the object.Therefore, even if RFID tags were miniaturized, there would not be asuitable location on the exterior surface of a needle or scalpel bladefor placement of a tag. The current state of needle counting technologyconsists of many variations of mechanical needle counting devices. Thesedevices provide numbered spaces, slots, foam blocks, magnets, amongothers, usually all carried within a hard plastic clam-shell type of boxthat can be snapped shut after the box is filled with sharps. Thesedevices vary primarily in size and needle capacity, but alsodifferentiate through features such as magnetic areas where needles andblades may be placed to prevent falling out, fixtures for removingneedles from syringes and blades from scalpels, safety hinges, etc.

We have polled various nursing staffs and have found almost unanimousinterest in a solution that would automate the counting of needles,and/or validate the manual counts, and/or assist in entering thesecounts into the electronic medical record. A need exists for a productthat can provide these various functions.

SUMMARY

A preferred embodiment of the present disclosure has a housing of a hardmaterial, preferably plastic. One or more hinges are provided wherebythe container can be opened, usually along a bisecting line, to revealtwo “tray-like” halves with walls of some height, intended to containsharps throughout a procedure. On the interior of one, or the other, orboth halves of the container, there is a marked foam material. The sideor sides of the container whose interior is covered with a foam materialwill continue to be used to facilitate needle/sharps counting in anidentical manner to current products. In current products, this isaccomplished by using a foam that is easily punctured by the sharps. Thefoam is of a sufficient thickness and possesses the proper materialproperties to hold the sharps in place after the sharps are insertedinto the foam. The foam surface traditionally assists in counting byproviding a printed grid pattern on the surface of the foam material.The user places one sharp per grid space, thereby making counting easierby providing visual cues that are easy to see.

In addition to providing this standard functionality, the presentinvention provides an “electronic count” of the needles and other sharpsplaced into this foam material with a printed grid pattern. To providethe electronic count, unlike the prior art devices which use a uniformpiece of foam, the present invention uses layers of conductive andnon-conductive foam (a multi-layer foam assembly). As the sharps arepunctured through the multi-layer foam assembly, one or more circuitswill be completed or the capacitance between the layers will be changedfrom a baseline capacitance measurement. The status of these variouscircuits or the change in capacitance values communicates the presenceand/or quantity of sharps in the foam assembly, thus providingadditional information to the user.

In one embodiment, a single layer of conductive foam forms the groundplane, and is commonly accessible to all sharps placed in themulti-layer foam assembly. The ground plane could be the top or bottomlayer of the foam assembly. A second layer is comprised of conductivefoam patches or grid elements, separated by non-conductive material,such as non-conductive foam, such that the single layer has some numberof conductive areas, separated completely (electronically isolated) fromall other conductive areas in the layer. Presumably the conductive areascollectively comprise the great majority of surface area compared to thenonconductive areas. A middle layer of nonconductive material, such asnonconductive foam, separates the two layers described above.

The single common ground plane foam layer has a lead, in the form of awire or other conductive trace, connecting it to the ground pin of ananalog or digital circuit component. Each conductive region of thesecond layer has a lead connecting it to the same circuit.

The multi-layer foam assembly, when constructed in the above manner,represents some number of open circuits connected to a circuit capableof sensing whether these circuits are open or closed. The act ofpiercing the multi-layer foam assembly will dramatically lower theresistance in the circuit, in essence closing the open circuit.

Other embodiments of the invention include, but are not limited to amulti-layered foam assembly with more than the three layers describedhere. Additional top and bottom layers may be desirable for protectionof the foam, to facilitate printing, to add adhesive, etc. Adding moreintermediate layers (both those containing a grid pattern of conductiveareas, and those that constitute a single ground plane) provides formore opportunities for the sharp to close the electrical circuit. Bystaggering or offsetting multiple layers, one could provide more preciselocation information of the sharps. This could allow for multiple sharpsaccidentally placed in the same printed grid space to be individuallyrecognized and therefore reduce the possibility for errors. Theembodiment described above is referred to as an X to ground Y to groundtype of sensing. Strips of foam positioned to define rows in one layerand columns in another layer, with or without a ground plane, may alsobe used.

In yet other embodiment, the grid formed by the upper and lower layersof conductive foam strips also forms a series of capacitors at theintersection points of the rows and columns. For example, a foamassembly may be constructed of 10 conductive foam strips in a top layeroriented in horizontal rows, and 5 conductive foam strips oriented invertical columns, separated by a nonconductive layer. In thisconfiguration, there would be 50 intersection points, creating 50distinct capacitors. The capacitance of each intersection point could bemonitored by a control unit such as a microcontroller; additionally thismicrocontroller may be supplemented by a specialized integrated circuitsuch as a capacitive sensing module (CSM) that is adapted for sensing alarge number of capacitors in a grid formation. An example of such a CSMmodule is the Microchip mTouch TB3064.

In this embodiment, the capacitive sensing module would be connected toeach of the X and Y rows and columns, and would be capable of addressingone row/column combination at a time by selecting the appropriateinput/output channels and grounding the others. For each row/columncombination, the capacitance of the intersection point is measured usingone of several techniques. These techniques include, but are not limitedto, the relaxation oscillator technique, charge time vs. voltagetechnique, or the voltage divider technique. The Microchip mTouch TBS064 uses the relaxation oscillator technique. In this technique, thecontrol unit or CSM contains an RC oscillator circuit which uses as itscapacitance the capacitance of the row/column intersection. Thus thecapacitance of the row/column intersection determines the oscillator'sfrequency which is monitored by the CSM. The CSM establishes a baselinecapacitance value based on, among other factors, a predetermined orpreprogrammed value or historical measured values. When a change incapacitance occurs between measurements, or when the measuredcapacitance differs by some threshold amount from the baseline value,the CSM signals the control unit. The CSM will measure every row/columncombination in rapid succession. The control unit may apply somefiltering to the data received from the CSM before determining that thechange in capacitance does indeed represent a sharp puncturing the foam.For example, the control unit may apply some averaging to the data tofilter out sporadic noise.

In yet other embodiments involving magnetic materials, pairs ofelectrical contacts may be provided, for example on a magnetic surfaceused to hold sharps safely inside the container. These electricalcontacts would enable circuitry to determine which pairs of contacts areopen and which pairs of contacts are shorted by the positioning of ascalpel blade or other sharp across a pair of contacts. Contacts couldbe positioned on a blade removal tool with the number of times a bladeis inserted into the tool counted. Means can be provide to enable an “incount” to be taken. An “in count” is a count of the number of sharpsavailable for use in the particular procedure. By comparing the “incount” to an “out count” (the number of sharps returned), an electronicverification that all sharps are accounted for can be provided. Byproviding RFID tags on sharps containers, data at the container aboutthe container's contents can be transmitter for further use. The presentinvention includes various methods of using the different embodiments ofdisclosed sharps containers. The present invention automates thecounting of needles, validates manual counts, and can assist in enteringthese counts into the electronic medical record. Those advantages andbenefits, and others, will be apparent from the description containerherein below.

BRIEF DESCRIPTION OF THE DRAWINGS

For the present invention to be easily understood and readily practiced,embodiments of the present invention will now be described, for purposesof illustration and not limitation, in conjunction with followingfigures.

FIG. 1 illustrates a container.

FIG. 2 illustrates the container of FIG. 1 in an opened condition.

FIGS. 3A and 3B illustrate a multi-layer foam assemble implementing anisolated pad to ground type of sensing.

FIG. 4 is a block diagram of exemplary hardware which may be used tointerrogate the multilayer foam assembly of FIGS. 3 A and 3B.

FIGS. 5A, 5B, and 5C illustrate a multi-layer foam assemble implementingan X—Y type of sensing.

FIG. 6 a variation of the multi-layer foam assembly shown in FIGS. 5 A,5B, and 5C modified to add a ground layer to implement an X to ground Yto ground type of sensing.

FIG. 7 illustrates a sharps container having on the left side amulti-layer foam assembly and on the right said a magnetic materialhaving a plurality of electrical contacts.

FIG. 8 illustrates a sharps container having on the left side amulti-layer foam assembly and on the right said a magnetic materialhaving a blade removal tool having a pair of electrical contacts.

FIG. 9 is a flow chart illustrating the steps performed by theuser/operator and the hardware shown in FIG. 4.

FIG. 10 shows an example flow chart illustrating one method of using asharps container constructed with discrete conductive pads.

FIGS. 11A and 11B show an example flow chart illustrating one method ofusing a sharps container constructed with an X-Y grid and no commonground plane.

FIGS. 12A and 12B show an example flow chart illustrating one method ofusing a sharps container constructed with an X-Y grid, no common groundplane, and which generates an “in count”.

FIGS. 13A and 13B show an example flow chart illustrating one method ofusing a sharps container constructed with an X-Y grid, no common groundplane, and which generates an “in count” with a button or switch.

FIG. 14 shows an example flow chart illustrating one method of using asharps container having contacts on magnetic pads.

FIG. 15 shows an example flow chart illustrating one method of using asharps container having contacts carried by a blade removal tool.

DETAILED DESCRIPTION

Illustrated in FIG. 1 is a container 10 constructed according to theteachings of the present invention. The container 10 is constructed of ahousing 12 of a hard material, preferably plastic. A latch comprised ofan upper part 14 and a lower part 16 is provided. Those of ordinaryskill in the art will recognize that the side of the housing 12 oppositethe side carrying the latch, which is not visible in FIG. 1, carries oneor more hinges which enable the container 10 to be opened as shown inFIG. 2.

The hinges are usually provided along a bisecting line 18 seen in FIG.2. When the housing 12 is open as shown in FIG. 2, two “tray-like”halves 20, 22 with walls of some height are provided for the purpose ofcontaining the sharps used throughout a procedure. The hinges may be ofa type that can be separated and re-joined, allowing the user to placeeach half 20, 22 of the housing 12 in a different location. The hingesmay be of a locking safety type that allow for the separation of thedetachable hinges only when the container 10 is opened, and not when inthe closed position.

Each half 20, 22 of the container 10 carries a specialized componentcomprised of, for example, a foam material 24, 26, respectively, shownin FIG. 2, or a magnetic material (not shown in FIG. 2). When magneticmaterial is present, the magnetic material is helpful as a “holdingplace” for needles and other metallic sharps during the procedure. Inthe prior art, this magnetic material is not used to facilitate any typeof counting. However, as will be described below, in the presentinvention, this magnetic material may be modified to enable “outcounting,” i.e. when a sharp is no longer being used in the procedureand is returned to the sharps container.

In one embodiment, this disclosure focuses on the side(s) of thecontainer 10 normally carrying a foam material. It should be noted thatimplementations of the present invention will, however, need to considervarious features. For example, one embodiment of the invention mayrequire circuitry on both sides of the container 10 connected by wiresor flexible PCB material. That may conflict with the desire to separatethe two halves of the container 10. Also, the effects of the magneticmaterial, if any, on an RFID transponder will need to be considered.

The sides of the container 20, 22 carrying the foam material 24, 26,respectively, are used to facilitate sharps counting in an identicalmanner to prior art products. In prior art products, the foam materialis a single piece of foam having a printed grid pattern 28 on thesurface of the foam material. Counting is accomplished by using a foamthat is easily punctured by the sharps. The foam is of a sufficientthickness and density to hold the sharps in place after the sharps areinserted into the foam. The user places one sharp per grid space therebymaking counting easier by providing visual cues that are easy to see.

In addition to providing that standard functionality, this inventionprovides an “electronic count” of the sharps placed into foam pieces 24,26 carrying the printed grid pattern 28. To provide the electroniccount, unlike the prior art devices which use a single layer of foam,the present invention uses layers of conductive and non-conductive foam(a multi-layer foam assembly). As the foam is punctured by insertion ofsharps, a circuit is completed. The status of these various circuitscommunicates the presence and/or quantity of sharps in the foam, thusproviding additional information to the user.

In one embodiment illustrated in FIGS. 3A and 3B, the multi-layer foamassembly 30 comprises a single layer of conductive foam 32 forming aground plane that is commonly accessible to all sharps placed in themulti-layer foam assembly 30. The ground plane 32 could be the top orbottom layer of the foam assembly 30.

A second layer 34 is comprised of conductive foam patches or gridelements 36 separated by non-conductive material 38, such asnon-conductive foam, such that the second layer 34 has some number ofconductive areas separated completely (i.e., electronically isolated)from all other conductive areas in the layer. Presumably the conductiveareas collectively comprise the great majority of surface area comparedto the nonconductive areas. The conductive foam patches or grid elements36 may or may not correspond to a grid pattern 28 printed on the top ofthe foam piece 24/26. A middle layer 40 of nonconductive material, suchas nonconductive foam, separates the layers 32 and 34. In an alternativeembodiment, one can imagine conductive inserts 36 placed into a layer ofnonconductive material in a manner such that the conductive inserts donot extend to the bottom of the layer 34. In such an embodiment, themiddle layer 40 could be eliminated.

Turning to FIG. 4, the single common ground plane foam layer 32 has alead, in the form of a wire, conductive trace, or the like 42,connecting the ground plane foam layer 32 to a ground pin of an analogor digital circuit 44. Shown in FIG. 4 is the first row of conductiveregions labeled 1,1 through 1,9. Each conductive region 36 of the secondlayer 34 has a lead in the form of a wire, conductive trace, or the like46 connecting the region 36 to the circuit 44. The multi-layer foamassembly 30, when constructed in this manner, represents a plurality ofopen circuits connected to the circuit 44. Piercing the multi-layer foamassembly 30 with a sharp, shorts the pierced conductive region 36 to theground plane, dramatically lowering the resistance in that circuit and,in essence, closing the open circuit. The circuit 44 is capable ofsensing whether each of the plurality of circuits between the conductiveregions 36 and the ground plane 32 is open or closed. The number ofcircuits depends on the number of distinct conductive regions 36 thatare constructed in the second foam layer 34. That will determine thenumber of sharps that are countable by the device.

The circuit 44 used to determine the open/closed status of each circuitbetween the conductive regions 36 and the ground plane 32 may be acommon microcontroller with a sufficient number of I/O pins. Thismicrocontroller may poll the circuits in response to a command fromanother circuit component, or may automatically do so based on a timer.The microcontroller may employ further logic to change the timing ofthis polling based on activity or on some other type of sensor inputsuch as motion sensing. The microcontroller or another circuit componentreceiving the data representative of whether each circuit between theconductive regions 36 and the ground plane 32 is open or closed may logthe data over some period, or may communicate the data to a secondarylocal or remote device 50 having a memory 52 for storage (such as in adigital count sheet or electronic medical record), a display 54, such ason a local LCD, perhaps on the container 10 itself, or more likely on aremote LCD screen.

Part of this secondary device 50 may be an RFID transponder or tag 56.The transponder 56 will likely be of the passive or Battery-AssistedPassive (BAP) type. The transponder 56 responds to commands from anearby RFID reader 58 communicating through an antenna 60 to supply thetransponder's 56 unique identification number (UID), as well asadditional memory fields.

These additional memory fields may be programmed by the manufacturer andlocked, and later used to identify the type or other characteristics ofthe item that carries the RFID tag. For example, the transponder 56 onthe sharps container 10 could indicate to the interrogating reader 58various attributes of the sharp counter such as:

-   -   The manufacturer of the sharps counter    -   Date of Manufacture/Lot number, etc.    -   Intended for which type(s) of sharps    -   Maximum capacity of sharps

The memory field of the transponder 56 may have this informationdirectly encoded in, for example, an ASCII character format, so that theinterrogating reader 58 and any computer system 62 that is receiving thedata does not need a look-up table to interpret it. Alternatively, eachpiece of information is represented by a code that is used to look upits meaning. Alternatively, a look-up table simply using ranges of UIDsmay be used for the above purpose. This is generally too cumbersome toimplement.

The RFID reader 58 polls the transponder 56 on the container 10, whichcommands the circuit 44 on-board the container 10 to query all of thecircuits between the conductive regions 36 and the ground plane 32 andrespond with the quantity of open/closed circuits. The RFID transponder56 communicates this variable data, along with any other data itcontained as discussed above. The RFID reader 58 is comprised of or isconnected to a computer system 62, which is capable of interpreting boththe static and variable data fields passed to it from the RFIDtransponder 56. The RFID reader 58 and computer system 62 could serve asthe control/display unit responsible for interpreting, processing,storing, and communicating the data externally to a record keepingsystem, and/or displaying the information on a screen. It should benoted that because the RFID reader 58 and computer system 62 alwaysassociate the static and variable data with a UID, and would have theability to properly associate multiple data sets with theircorresponding UIDs, a single reader 58 could interrogate any number ofRFID tagged sharps containers and be able to record/report/display dataabout each individual container, even when read by the same readersimultaneously.

For example, two different containers could be used, each with adifferent capacity and each intended for a different type of needle. Adisplay connected to the RFID reader/computer could display thefollowing:

-   -   CONTAINER #1: Needle Type A: 5 of 20 needles present    -   CONTAINER #2: Needle Type B: 3 of 10 needles present

It is envisioned that the RFID reader/antenna would be a multi-purposereader/antenna, such as the reader/antenna available from ClearCountMedical Solutions, Inc. of Pittsburgh Pa. Such a reader is intended forscanning sponges, towels, and other items tagged with RFID tags. Thereader 58 may not be permanently mounted within reading distance of theRFID tagged sharps container, but instead the reader could be broughtnearby when a count is desired. Alternatively, the RFID reader 58 couldbe of a tunnel-style or bucket-style, such as ClearCount's receptaclereader on its SmartSponge System. In this scenario, the sharps containercould be placed in the receptacle when a count is wanted, such as at thevery end of a procedure.

As an alternative to the device 44 polling the circuits between theconductive regions 36 and the ground plane 32 when instructed to by theRFID transponder 56, the polling could be done periodically by circuit44 and the results saved in memory 52. Then when the reader 58 polls thetransponder 56, the transponder 56 transfers the data from the memory 52to the reader 58.

As an alternative to periodic querying of the RFID tagged sharpscontainer 10, a more permanently positioned dedicated base station (notshown) could be employed. A base station would be in communication withthe sharps counter 10 through the transponder 56 or through physicalconnections. The use of a dedicated base station using physicalconnections could have the further advantage of allowing for someportion of the circuitry needed on the sharps container to be placed ona reusable device, allowing the disposable sharps container to be madeless complex and expensive.

The microprocessor 44 and secondary device 50 on the container 10 may bepowered by one or more of the following means:

-   -   On-board battery, such as a small, light, and inexpensive cell        that provides sufficient power for a single surgical procedure,        and is intended to be disposed along with the sharps container        at the end of the procedure.    -   If an RFID transponder or similar circuit is employed on the        container, this device may ‘harvest’ ambient energy from an        interrogating reader. This is commonly done with RFID        transponders and is in fact how passive transponders function.        It is conceivable that enough of this power is diverted to        temporarily power the microcontroller 44 and secondary device 50        while the reader is in proximity.    -   A base station containing a power supply of any known type, with        physical contact connectors, can provide power to the        microprocessor 44 and secondary device 50 on the container 10.        It is presumed that this would be a reusable piece of hardware.    -   A capacitor is used on-board the container and is either        pre-charged or is charged via one of the two means described        above, and allows for continuity of power for some time after        the ambient energy or base station power source is removed.

It is possible to envision a multi-layered foam assembly with more thanthe three layers described here. Additional top and bottom layers may bedesirable for protection of the foam, to facilitate printing, to addadhesive, etc. Adding more intermediate layers (both those containing agrid pattern of conductive areas, and those that constitute a singleground plane) provides for more opportunities for the sharp to close theelectrical circuit. By staggering or offsetting multiple layers, onecould provide more precise location information of the sharps. Thiscould allow for multiple sharps accidentally placed in the same printedgrid space to be individually recognized and therefore reduce thepossibility for errors.

For example, if the printed grid size is 1 cm×1 cm, staggering oroffsetting of multiple layers results in an effective electrical gridsize of 0.25 cm×0.25 cm. That could reduce errors significantly. Othervariations of the present invention involve the substitution of othermaterials for those described herein, the use of additionalnon-functional layers for spacing, adhesion, etc. among others.

Variations of the multi-layer foam assembly are contemplated. Onevariation shown in FIGS. 5 A, 5B, and 5C provides a first grid pattern71 of conductive foam and a second grid pattern 72 of conductive foam.Although each of the grid patterns alone does not provide unique gridlocations, when stacked as shown in FIG. 5C, the grid patterns 71, 72together provide a series of unique grid locations for a sharp placedthrough them by means of providing a unique combination of X and Ycoordinates. Each conductive foam ‘column’ and ‘row’ is treated as aninput to a circuit 44 of the type shown in FIG. 4, and additional logicis provided to calculate the X and Y coordinates (i.e., the position orlocation) of sharps present based on the collective status of the columnand row circuits. Depending on the capabilities and available pins onthe circuit used to determine if a circuit is open or closed, a groundplane 74 may be necessary as shown in FIG. 6. The multi-layer foamassembly of FIGS. 5 A, 5B, and 5C is used to implement an X—Y type ofsensing while the multi-layer foam assembly of FIG. 6 is used toimplement an X to ground Y to ground type of sensing. These variationsmay be polled by the circuit shown in FIG. 4 with logic added tocalculate position information.

FIG. 7 illustrates another type of sharps container 80. The sharpscontainer 80 has, on the left side, a multi-layer foam assembly of thetype previously described. On the right side of the container 80, amagnetic material 82 is provided. The magnetic material 82 may beprovided with a plurality of electrical contacts 84. When a used scalpelblade is positioned between a pair of contacts 84, a circuit is closedbetween those contacts indicating that a scalpel blade has been storedin the container 80. Circuitry of the type shown in FIG. 4 may be usedto periodically poll pairs of contacts 84 to determine which are openand which have been closed by the positioning of a blade therebetween.The magnetic material will hold the used blade on the contacts 84. Aswitch 66 (see FIG. 4) may be used to manually “in count” the number ofscalpel blades used for the procedure. A blade removal tool 86 may alsobe provided as is known in the art.

FIG. 8 illustrates another type of sharps container 90. Sharps container90 is similar to sharps container 80 in that sharps container 90 has, onthe left side, a multi-layer foam assembly of the type previouslydescribed and, on the right side, a magnetic material 82. Sharpscontainer 90 does not have the plurality of contacts 84. Rather, a bladeremoval tool 86′ is equipped with a pair of electrical contacts whichenable a circuit to be closed each time a scalpel blade is inserted intothe removal tool. In that manner, a count of the returned blades(referred to as an “out count”) can be maintained. A switch 66 (see FIG.4) may be used to manually “in count” the number of scalpel blades usedfor the procedure. In either the embodiment shown in FIG. 7 or theembodiment shown in FIG. 8, comparing the “in count” with the “outcount” provides an electronic verification that all blades have beendelivered to the sharps container 80, 90.

FIG. 9 illustrates a flow chart of the steps performed by auser/operator and the hardware shown in FIG. 4. In FIG. 9, and the otherfigures illustrating methods, rectangles represent user actions whileovals represent hardware actions. In FIG. 9, the process may begin withthe optional step 100 of the user entering an “in count.” Although notrequired, an “in count” enables an electronic verification that allsharps are accounted for. At step 102 the circuit 44 polls all of thecircuits to which it is attached to determine which are open, which areclosed and, depending on the configuration of the sharps container, thelocation of the circuit. The polling may be initiated by the user or atimer. Polling is accomplished in a number of ways:

-   -   In the embodiment of FIGS. 3 A and 3B, the circuit 44 determines        for each conductive element 36 whether a sharp has penetrated        the conductive element and penetrated the ground plane 32.    -   In the embodiment of FIGS. 5 A, 5B, and 5C, the circuit 44        determines if a sharp has penetrated both a row and a column of        conductive material, and if so, the row number and column        number.    -   In the embodiment of FIG. 7, the circuit 44 determines which        pairs of electrical contacts are open and which are shorted.    -   In the embodiment of FIG. 8, the circuit 44 keeps track of how        many times a blade has been inserted in the blade removal device        86′.

After the polling is completed, the results are stored in memory 52 atstep 104.

At any time, the user may request a count of the returned sharps asshown at step 106. In the embodiment of FIG. 4, the reader 58 andantenna 60 are used to send the request to transponder 56. In otherhardware configurations, the container may be brought into proximity tothe antenna 60. When the antenna 60 is brought into rage of thetransponder 56, the transponder transmits its unique ID, any informationin fixed fields as discussed above, and the results of the polling takenfrom memory 52 as shown at 108. Finally, the results of the polling,which represents a count of the returned sharps, may be compared to the“in count” to verify that all sharps are accounted for or to indicatethat one or more sharps are not accounted for as shown at step 110.

More detailed explanations of various methods of operation areillustrated in FIGS. 10-15. FIG. 10 shows at 1000 an example flow chartillustrating one method of using a sharps container constructed withdiscrete conductive pads. A microcontroller iterates through cells on aneedle counter included in the sharps container, and generatesinformation related to the number of needles inserted onto the needlecounter based on the number of closed circuits formed by the insertedneedles penetrating conductive layers with discrete conductive pads.

At 1002, a user inserts a number of needles into cells on the needlecounter which has multiple conductive layers (e.g., two or threelayers). At least one of the conductive layers has the discreteconductive pads. The needles penetrate both or three layers and close acertain number of circuits in the cells at 1006. After an RFIDtransponder or tag is powered up by an RFID receiver at 1008, themicrocontroller iterates through each cell, and generates informationrelated to the number of the inserted needles based on the number ofclosed circuits that are detected at 1010. Then the microcontrollerprovides, through the RFID transponder or tag, information related tothe number of closed circuits along with additional information to theRFID receiver upon request at 1012. The RFID receiver identifies thereceived information and displays a final count of the needles insertedinto the cells on the needle counter on a system display at 1014. Theuser can read the final count of the inserted needles on the systemdisplay at 1004. Optionally, the RFID receiver may transmit the receivedinformation to a central server which logs the final count in anelectronic record at 1016.

FIGS. 11A and 11B show at 1100 an example flow chart illustrating onemethod of using a sharps container constructed with an X-Y grid and nocommon ground plane. Based on stacked grid patterns, a microcontrolleriterates through cells on a needle counter included in the sharpscontainer, and generates information related to the number of needlesinserted onto the needle counter based on the number of closed circuitsdetected.

Specifically, at 1102, a user inserts a number of needles into cells onthe needle counter which includes multiple conductive layers (e.g., twoor three layers). Two or more of the conductive layers include differentgrid patterns which are stacked together to provide a series of uniquegrid locations for an inserted needle using a unique combination ofcoordinates (e.g., X and Y coordinates). The needles penetrate both orthree layers and close a certain number of circuits in the cells at1106. After an RFID transponder or tag is powered up by an RFID receiverat 1108, the microcontroller iterates through cells to count the closedcircuits at 1110. The microcontroller starts with a first cell formed bythe stacked grid patterns, e.g., a cell at the crossing of a first“column” (n=1) and a first “row” (m=1) of the stacked grid patterns, andthen proceed to check all other cells.

For a particular cell, the microcontroller determines whether a circuitis closed at 1112. If no closed circuit is detected, the particular cellis skipped at 1114. On the other hand, if a closed circuit is detectedat the particular cell, the microcontroller marks, at 1124, theparticular cell as having a needle. Then, a next cell is chosen to bechecked until all cells have been visited by the microcontroller.

To choose a next cell, the microcontroller determines, at 1116, whetherthe particular cell is at the last column of the stacked grid patterns,e.g., whether n<nmax. If the particular cell is not at the last column,the next cell is chosen at the crossing of a next column (e.g., n isincremented) and the same row of the particular cell, at 1118. If theparticular cell is at last column, then the microcontroller determines,at 1120, whether the particular cell is at the last row of the stackedgrid patterns, e.g., whether m<mmax. If the particular cell is at thelast row, it means all cells have been checked and the number ofdetected closed circuits is returned for reporting. If the particularcell is not at the last row, the next cell is chosen at the crossing ofa next row (e.g., m is incremented) and the first column of the stackedgrid patterns (e.g., n is set to be 1), at 1122.

Then the microcontroller provides, through the RFID transponder or tag,information related to the number of closed circuits along withadditional information to the RFID receiver upon request at 1126. TheRFID receiver identifies the received information and displays a finalcount of the needles inserted into the cells on the needle counter on asystem display at 1128. The user can read the final count of theinserted needles on the system display at 1104. Optionally, the RFIDreceiver may transmit the received information to a central server whichlogs the final count in an electronic record at 1130.

FIGS. 12A and 12B show at 1200 an example flow chart illustrating onemethod of using a sharps container constructed with an X-Y grid, nocommon ground plane, and which generates an “in count.” Amicrocontroller polls dedicated cells to count the number of new needlesthat are checked out for use to establish the “in count” of the newneedles. Then, based on stacked grid patterns, the microcontrolleriterates through cells to count the number of needles that are returnedafter use to the sharps container for comparison with the “in count.”

A user unwraps a number of new needles, and inserts the new needles intodedicated cells on the needle counter before use at 1202. The needlecounter includes the stacked grid patterns. The needles penetrate bothor three layers and close a certain number of circuits in the dedicatedcells at 1204. The microcontroller sets a flag for each closed circuitformed by an inserted needle at 1206. After the user checks out acertain number of new needles for use at 1208, the microcontrollercounts the number of open circuits resulted from the checked-out needlesat 1210. Then the microcontroller provides reports of the number of thechecked-out needles to an RFID receiver upon request at 1212.

At 1214, the user inserts a certain number of checked-out needles afteruse into cells on the needle counter. The microcontroller counts thenumber of the used needles based on the number of closed circuits thatare detected similar to what is described for FIG. 11. Then themicrocontroller provides, through an RFID transponder or tag on thesharps container, information related to the number of the detectedclosed circuits, the “in count,” and additional information to the RFIDreceiver upon request at 1218. The RFID receiver identifies the receivedinformation and displays a final count of the needles returned after useand the “in count” for comparison on a system display at 1220. The usercan read the final count of the needles returned after use and the “incount” on the system display at 1216. Optionally, the RFID receivertransmits the received information to a central server for recording at1222.

FIGS. 13A and 13B show at 1300 an example flow chart illustrating onemethod of using a sharps container constructed with an X-Y grid, nocommon ground plane, and which generates an “in count” with a button orswitch. A microcontroller counts the number of new needles that arechecked out for use to establish the “in count” of the new needles basedon a user's manual input using the button or switch. Then, based on thestacked grid patterns, the microcontroller iterates through cells tocount the number of the needles that are returned after use to thesharps container for comparison with the “in count.”

A user unwraps a number of new needles, and presses a button or switchonce for each needle to be checked out for use at 1302. Themicrocontroller counts the number of checked-out needles based on theuser's manual input through the button or switch to establish the “incount” of the new needles, at 1304. Then, at 1306, the microcontrollerprovides reports of the number of checked-out needles to an RFIDreceiver upon request.

The microcontroller counts the number of the needles that are returnedafter use based on the number of closed circuits that are detectedsimilar to what are described for FIGS. 11A and 11B and FIGS. 12A and12B. Then, the microcontroller provides, through an RFID transponder ortag on the sharps container, information related to the number of thedetected closed circuits, the “in count,” and additional information tothe RFID receiver upon request at 1308. The RFID receiver identifies thereceived information and displays a final count of the needles returnedafter use and the “in count” for comparison on a system display at 1310.Optionally, the RFID receiver may transmit the received information to acentral server for recording at 1312.

FIG. 14 shows at 1400 an example flow chart illustrating one method ofusing a sharps container having contacts on magnetic pads. Amicrocontroller iterates through pairs of contacts on a magnetic surfaceincluded in the sharps container, and generates information related tothe number of blades inserted into the sharps container based on thenumber of closed circuits formed by the inserted blades spanning thepairs of contacts.

At 1402, a user inserts a number of blades removed from scalpels ontothe pairs of contacts on the magnetic surface in the sharps container at1402. Each of the blades spans a pair of contacts, and thus closes acircuit at 1406. After an RFID transponder or tag is powered up by anRFID receiver at 1408, the microcontroller iterates through the pairs ofcontacts, and generates information related to the number of theinserted blades based on the number of closed circuits that are detectedat 1410. Then the microcontroller provides, through the RFID transponderor tag, information related to the number of closed circuits along withadditional information to the RFID receiver upon request at 1412. TheRFID receiver identifies the received information and displays a finalcount of the inserted blades on a system display at 1414. The user canread the final count of the inserted blades on the system display at1404. Optionally, the RFID receiver may transmit the receivedinformation to a central server which logs the final count in anelectronic record at 1416.

FIG. 15 shows at 1500 an example flow chart illustrating one method ofusing a sharps container having contacts carried by a blade removaltool. A microcontroller counts the number of blades that are removed bythe blade removal tool based on the number of times a circuit formed bycontacts on the blade removal tool being closed.

At 1502, a user inserts a blade to be removed onto the blade removaltool which includes contacts on either side. The blade spans a gapbetween the contacts on either side of the tool, and thus closes thecircuit formed by the contacts at 1506. The microcontroller flags thatthe circuit has been closed at 1508. Then the user pulls the scalpelback, and removes the blade at 1510. The microcontroller detects thatthe circuit is open, and increments the count of removed blades at 1512.Another blade can be inserted onto the blade removal tool to be removed,and the microcontroller keeps counting the times of the circuit on thetool being closed.

After all blades are removed using the blade removal tool, themicrocontroller provides, through an RFID transponder or tag,information related to the count of the removed blades along withadditional information to an RFID receiver upon request at 1514. TheRFID receiver identifies the received information and displays a finalcount of the removed blades on a system display at 1516. The user canread the final count of the removed blades on the system display at1504. Optionally, the RFID receiver may transmit the receivedinformation to a central server for recording at 1516.

These flow charts are not intended to be the sole methods of operation.Rather, the flow charts are intended to illustrate the variety ofmethods than can be performed using the disclosed sharps containers.

It is known in the art to tag the outer packaging of items, includingsurgical items, with RFID transponders for the purpose of inventorycontrol. In this document, the RFID reader 58 (see FIG. 4) and computersystem 62 could be configured to detect each needle package via an RFIDtag placed on the packaging material. This would establish an “in count”that would accurately represent the number of needles used in thesurgical procedure. The reader and computer system could then comparethis “in count” to the number of needles contained in the sharpscontainer 10 (the “out count”) via the methods and apparatus describedherein. That would reduce the possibility for human error in the “incounting” process. The same is possible for scalpel blades.

Furthermore, the RFID tag associated with the needle or scalpel bladecould be located inside the packaging of the needle or scalpel blade.The packaging of the suture or needle is often of the foil peel-pouchtype and thus can be used to shield or detune an RFID transponder. TheRFID transponder could be placed either removably or irremovably insidethe foil packaging such that the tag cannot be read until the packagingis opened, or until the packaging is opened and the RFID transponder isremoved from the packaging. This would establish an “in count” thatwould accurately represent the number of needles used in the surgicalprocedure. The reader and computer system could then compare this to thenumber of needles contained in the sharps container via the methods andapparatus described herein. This would further reduce the possibilityfor human error in the “in counting” process, because only needles inpackages that were opened could be counted in.

While the present invention has been particularly shown and describedwith reference to the preferred embodiments thereof, it will beunderstood by those skilled in the art that various changes in form anddetail may be made therein without departing from the spirit and scopeof the invention. The following claims are intended to cover suchchanges in form and detail.

1. A system for electronically counting sharps, said system comprising:a disposable sharps container defining a volume, said volume configuredto contain a plurality of sharps; and a remote device in communicationwith said disposable sharps container, wherein said disposable sharpscontainer and said remote device, are collectively configured toelectronically count a number of sharps placed within said volume. 2.The system of claim 1, wherein said disposable sharps container isconfigured to form a closed circuit when a sharp is placed within saidvolume.
 3. The system of claim 1, wherein said disposable sharpscontainer comprises a plurality of electronic contacts.
 4. The system ofclaim 1, wherein said disposable sharps container comprises a capacitivesensing module.
 5. The system of claim 1, wherein said remote device isfurther defined as a base station.
 6. The system of claim 1, whereinsaid disposable sharps container is physically connected to said remotedevice.
 7. The system of claim 1, wherein said remote device is in radiocommunication with said disposable sharps container.
 8. The system ofclaim 1, wherein said disposable sharps container further comprises atransponder and said remote device comprises a reader, said reader incommunication with said transponder.
 9. The system of claim 8, whereinsaid reader is a receiver.
 10. The system of claim 8, wherein saidtransponder is an RFID tag.
 11. The system of claim 1, wherein saidremote device comprises a memory unit, said memory unit storing saidnumber of sharps electronically counted in said disposable sharpscontainer.
 12. The system of claim 1, wherein said remote devicecomprises a microcontroller.
 13. The system of claim 1, wherein saidremote device comprises a display unit, and wherein said remote deviceis configured to display said number of sharps electronically counted insaid disposable sharps container on said display unit.